There is growing evidence that personality traits are affected by many genes, all of which have very small effects. As an alternative to the largely unsuccessful search for individual polymorphisms associated with personality traits, the authors identified large sets of potentially related single nucleotide polymorphisms (SNPs) and summed them to form molecular personality scales (MPSs) with from 4 to 2,497 SNPs. Scales were derived from two thirds of a large (N = 3,972) sample of individuals... Show moreThere is growing evidence that personality traits are affected by many genes, all of which have very small effects. As an alternative to the largely unsuccessful search for individual polymorphisms associated with personality traits, the authors identified large sets of potentially related single nucleotide polymorphisms (SNPs) and summed them to form molecular personality scales (MPSs) with from 4 to 2,497 SNPs. Scales were derived from two thirds of a large (N = 3,972) sample of individuals from Sardinia who completed the Revised NEO Personality Inventory (P. T. Costa, Jr., & R. R. McCrae, 1992) and were assessed in a genomewide association scan. When MPSs were correlated with the phenotype in the remaining one third of the sample, very small but significant associations were found for 4 of the 5e personality factors when the longest scales were examined. These data suggest that MPSs for Neuroticism, Openness to Experience, Agreeableness, and Conscientiousness (but not Extraversion) contain genetic information that can be refined in future studies, and the procedures described here should be applicable to other quantitative traits. Show less

Personality traits contribute to health outcomes, in part through their association with major controllable risk factors, such as obesity. Body weight, in turn, reflects our behaviors and lifestyle and contributes to the way we perceive ourselves and others. In this study, the authors use data from a large (N = 1,988) longitudinal study that spanned more than 50 years to examine how personality traits are associated with multiple measures of adiposity and with fluctuations in body mass index ... Show morePersonality traits contribute to health outcomes, in part through their association with major controllable risk factors, such as obesity. Body weight, in turn, reflects our behaviors and lifestyle and contributes to the way we perceive ourselves and others. In this study, the authors use data from a large (N = 1,988) longitudinal study that spanned more than 50 years to examine how personality traits are associated with multiple measures of adiposity and with fluctuations in body mass index (BMI). Using 14,531 anthropometric assessments, the authors modeled the trajectory of BMI across adulthood and tested whether personality predicted its rate of change. Measured concurrently, participants higher on Neuroticism or Extraversion or lower on Conscientiousness had higher BMI; these associations replicated across body fat, waist, and hip circumference. The strongest association was found for the impulsivity facet: Participants who scored in the top 10% of impulsivity weighed, on average, 11Kg more than those in the bottom 10%. Longitudinally, high Neuroticism and low Conscientiousness, and the facets of these traits related to difficulty with impulse control, were associated with weight fluctuations, measured as the variability in weight over time. Finally, low Agreeableness and impulsivity-related traits predicted a greater increase in BMI across the adult life span. BMI was mostly unrelated to change in personality traits. Personality traits are defined by cognitive, emotional, and behavioral patterns that likely contribute to unhealthy weight and difficulties with weight management. Such associations may elucidate the role of personality traits in disease progression and may help to design more effective interventions. Show less